DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 20 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 20 recites the limitation “preform configured to be drawn into the optical fiber of claim 16.” The limitation is indefinite as vague, because it is not clear from the claim what the preform requires to be configured to be drawn into the optical fiber of Claim 16. Examiner considers the claim to include any preform, which can be converted into the claimed optical fiber of Claim 16.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mishra (US 7,088,900) in view of Bookbinder et al. (US 2016/0304392) and Bookbinder et al. (US 2020/0049881).
Regarding Claim 1, Mishra (US’900) teaches a method of manufacturing a preform of an optical fiber, the optical fiber having a core region and a cladding region (Abstract), the method comprising: forming a porous cladding soot blank by depositing silica soot on a core cane, the core cane including a core portion having a composition corresponding to at least a portion of the core region of the optical fiber (col. 10, lines 3-32), and wherein a concentration of an alkali metal oxide in a core portion of the core cane is between 0.002 wt. % and 0.1 wt. % (col. 1, lines 64-66); exposing the porous cladding soot blank to a fluorine-doping precursor (col. 10, lines 37-51), the fluorine-doping precursor doping the porous cladding soot blank with fluorine to form a fluorine-doped porous cladding soot blank, the exposing comprising providing a flow of the fluorine-doping precursor to the porous cladding soot blank (col. 8, line 59 through col. 9, line 2); and consolidating the fluorine-doped porous cladding soot blank in presence or absence of a fluorine-doping precursor to form a consolidated fluorine-doped cladding cane (col. 10, lines 33-42, 44-50,54-65). US’900 teaches a depressed index cladding portion (inner cladding) with a relative refractive index Δ 3 with a relative refractive index in a range from -0.70% to -0.39% (Table 1; col. 1, lines 30-34) and therefore would have suggested a minimum Δ 3 (i.e. Δ 3min) less than -0.3%.
US’900 fails to teach SiCl4. Bookbinder et al. (US’392) teach an analogous method for forming an optical fiber, including forming a soot-deposited core, exposing the porous cladding soot blank to gas precursors, including SiCl4 and SiF4- [0047,0107] and additionally consolidating the cladding soot blank in the presence of SiCl4 [0087]-. It would have been obvious to a person of ordinary skill in the art at the time of invention to modify the process of US’900 by exposing the porous cladding soot blank to both a gas fluorine-doping precursor and a gas chlorine doping precursor (SiCl4) and consolidating the doped cladding soot blank while exposing the doped cladding soot blank to gas SiCl4, because US’392 is analogous art which suggests these steps to form an optical fiber, and also because US’392 suggests particular advantages to co-doping a core to achieve a desirable refractive index profile, attenuation, temperature profiles, and other properties [0008-0011]. Additionally, US’392 provides evidence to suggest it was conventional at the time of invention to expose a core to SiCl4 during consolidation and suggests this to increase doping with Cl and to create a cascading structure [0087,0090]; thus, it would have been obvious to perform the process of US’900 by exposing a core to SiCl4 during consolidation.
US’900 teaches 0.1 wt. % (1000 ppm) of alkali metal oxide an endpoint (col. 4, lines 42-44). The combination of US’900 in view of US’392 fails to teach between 0.5% and 1.5 % wt. Bookbinder et al. (US’881) is analogous art in the field of manufacturing a preform of an optical fiber with core and cladding regions, and in addition teaches that the core can contain 0.5 wt % of potassium oxide (K2O), which is an alkali oxide [0056]. Moreover, US’881 provides evidence that the concentration of K2O is a result-effective variable, known in the art to affect the attenuation performance (id). It would have been obvious to a person of ordinary skill in the art at the time of invention to modify the process of the combination of US’900 in view of US’392 by providing alkali metal oxide within the recited amounts through routine optimization.
US’392 teaches a concentration of about 32 % or 41% [0107]. The combination of references fails to teach the recited density/ concentration of SiCl4. Generally, differences in concentration will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration is critical. Additionally, it would have been obvious to modify the process of the combination of references by supplying SiCl4 within the recited range through routine optimization to achieve a desired concentration for a doped optical fiber.
Regarding Claim 2, US’900 (col. 3, lines 44-51; col. 5, lines 54-60; col. 2, lines 50-58) and US’392 [0054,0077] teach applying a fluorine doped silica glass outer cladding layer to a consolidated fluorine-doped cladding cane to form an optical fiber preform.
Regarding Claim 3, US’392 teaches a concentration of about 32 % or 41% [107], but the combination of references fails to teach the recited density/ concentration of SiCl4. Generally, differences in concentration will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration is critical. Additionally, it would have been obvious to modify the process of the combination of references by supplying SiCl4 within the recited range through routine optimization to achieve a desired concentration for a doped optical fiber.
Regarding Claim 4, US’900 teaches further forming a porous overclad soot blank by depositing silica soot on the consolidated fluorine-doped cladding cane; exposing the porous overclad soot blank to the fluorine-doping precursor (no SiCl4 is taught); and consolidating the porous overclad soot blank to form the preform, the preform comprising a cladding portion having a composition corresponding to the cladding region of the optical fiber (col. 10, lines 33-50).
US’900 fails to teach expressly a negative limitation of exposing the porous overclad soot blank to the fluorine-doping precursor in the absence of SiCl4. US’392 suggests that chlorine is an optional dopant [0054], which would thus be obvious to omit.
Regarding Claim 5, US’900 teaches a depressed index cladding portion surrounding the core portion and an outer cladding portion surrounding the depressed- index cladding portion, the depressed-index cladding portion having a first concentration of fluorine and the outer cladding portion having a second concentration of fluorine, the second concentration of fluorine being less than the first concentration of fluorine (Fig. 5; col. 6, lines 8-24 and 54-59). US’900 fails to teach expressly that the outer cladding has a lower concentration of fluorine than an inner cladding portion; however, US’900 shows fluorine concentrations varying by radius of the fiber with fluorine concentration low at the core with a step increase at around 5 micron, where a cladding is expected to begin and decrease gradually at around 10 microns and provides evidence that concentration of fluorine is a result-effective variable, known in the prior art to affect refractive index of a cladding, with more fluorine reducing refractive index (col. 6, lines 18-21). Furthermore, US’392 teaches that the cladding portion comprises a depressed-index cladding portion surrounding the core portion and an outer cladding portion surrounding the depressed- index cladding portion [0007,0056], that the fluorine concentration of an inner cladding can be more than that in the core [0069] and that the fluorine concentration of the outer cladding can be equal to or less than the minimum amount of fluorine in the core [0070] to achieve desirable optical properties (e.g. relative refractive index and propagation performance [0073]). It would have been obvious to a person of ordinary skill in the art at the time of invention to modify the process of US’900 with steps resulting in a cladding portion which comprises a depressed-index cladding portion surrounding the core portion and an outer cladding portion surrounding the depressed- index cladding portion, the depressed-index cladding portion having a first concentration of fluorine and the outer cladding portion having a second concentration of fluorine, the second concentration of fluorine being less than the first concentration of fluorine, because US’392 suggests both the steps and the relative amounts of fluorine to optimize properties of a resulting optical fiber.
Regarding Claim 6, US’900 fails to teach Δ4- Δ3min > 0.05%. US’900 teaches a depressed index cladding portion (inner cladding) with a relative refractive index Δ 3 with a relative refractive index in a range from -0.70% to -0.39% (Table 1; col. 1, lines 30-34) and embodiments in which both inner and outer cladding have Δ3- Δ2 = +- 0.05% (Claim 11; Figs. 5-6, 13-14; col. 6, lines 54-58), including embodiments where outer cladding exhibits a greater delta % than inner cladding (Figs. 13-14; col. 5, lines 49-54). US’392 suggests a refractive index difference between core and cladding of between 0.2%Δ and 0.5%Δ [0049], which is related to relative thicknesses and doping concentrations [0069-0070]. Additionally, US’392 teaches a depressed region inner cladding and an intermediate outer cladding relative index profile (Fig. 2A; [0056]). The combination of US’900 in view of US’392 having suggested the method of Claim 5 (See the rejection of Claim 5 above), Claim 6 simply recites desirable properties of an optical fiber which can be achieved through routine optimization of the obvious process of Claim 5. Additionally, the combination of references provides evidence that the relationship Δ4- Δ3min > 0.05% is an optimizable variable to achieve a desirable relative refractive index profile within an optical fiber.
Regarding Claim 7, US’900 teaches chlorine doping (col. 1, lines 62-63) in the core and optionally in the cladding, possibly at a lower concentration than in the core (col. 5, lines 10-27). US’392 expressly limits, even eliminates, chlorine from the outer cladding [0071]. Thus, it would have been obvious to a person of ordinary skill in the art at the time of invention to modify the combination of references with a greater chlorine concentration in an inner cladding than in an outer cladding through routine optimization of properties.
Claim(s) 8, 10, and 13-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mishra (US 7,088,900) in view of Bookbinder et al. (US 2016/0304392).
Regarding Claim 8, Mishra (US’900) teaches a method of manufacturing a preform of an optical fiber, the optical fiber having a core region and a cladding region (Abstract), the method comprising: forming a porous cladding soot blank by depositing silica soot on a core cane, the core cane including a core portion having a composition corresponding to at least a portion of the core region of the optical fiber (col. 10, lines 3-32), and wherein a concentration of an alkali metal oxide in a core portion of the core cane is between 0.002 wt. % and 0.1 wt. % (col. 1, lines 64-66); exposing the porous cladding soot blank to a fluorine-doping precursor (col. 10, lines 37-51), the fluorine-doping precursor doping the porous cladding soot blank with fluorine to form a fluorine-doped porous cladding soot blank, the exposing comprising providing a flow of the fluorine-doping precursor to the porous cladding soot blank (col. 8, line 59 through col. 9, line 2); and consolidating the fluorine-doped porous cladding soot blank in presence or absence of a fluorine-doping precursor to form a consolidated fluorine-doped cladding cane (col. 10, lines 33-42, 44-50,54-65). US’900 teaches a depressed index cladding portion (inner cladding) with a relative refractive index Δ 3 with a relative refractive index in a range from -0.70% to -0.39% (Table 1; col. 1, lines 30-34) and therefore would have suggested a minimum Δ 3 (i.e. Δ 3min) less than -0.3%.
US’900 fails to teach SiCl4. Bookbinder et al. (US’392) teach an analogous method for forming an optical fiber, including forming a soot-deposited core, exposing the porous cladding soot blank to gas precursors, including SiCl4 and SiF4- [0047,0107] and additionally consolidating the cladding soot blank in the presence of SiCl4 [0087]-. It would have been obvious to a person of ordinary skill in the art at the time of invention to modify the process of US’900 by exposing the porous cladding soot blank to both a gas fluorine-doping precursor and a gas chlorine doping precursor (SiCl4) and consolidating the doped cladding soot blank while exposing the doped cladding soot blank to gas SiCl4, because US’392 is analogous art which suggests these steps to form an optical fiber, and also because US’392 suggests particular advantages to co-doping a core to achieve a desirable refractive index profile, attenuation, temperature profiles, and other properties [0008-0011]. Additionally, US’392 provides evidence to suggest it was conventional at the time of invention to expose a core to SiCl4 during consolidation and suggests this to increase doping with Cl and to create a cascading structure [0087,0090]; thus, it would have been obvious to perform the process of US’900 by exposing a core to SiCl4 during consolidation.
US’392 teaches a concentration of about 32 % or 41% of SiCl4 [0107]. The combination of references fails to teach the recited density/ concentration of SiCl4. Generally, differences in concentration will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration is critical. Additionally, it would have been obvious to modify the process of the combination of references by supplying SiCl4 within the recited range through routine optimization to achieve a desired concentration for a doped optical fiber.
Regarding Claim 10, US’900 teaches drawing an optical fiber from a preform comprising a fluorine-doped cladding cane (col. 5, lines 6-9; col. 9, lines 48-51; col. 10, lines 42-67) and an attenuation at 1550 nm of less than 0.175 dB/km (Claims 15-16). US’900 fails to teach an attenuation <0.16 dB/km at 1583 nm. However, since it is standard to report measurements at a wavelength of 1550 nm and not at 1570 nm, 1583 nm, and 1590 nm, it is not clear whether a drawn optical fiber in US’900 would exhibit the claimed properties. Likewise, US’392 teaches an attenuation of less than 0.17 dB/km at 1550 nm (Abstract), including less than 0.16 dB/km and less than 0.15 dB/km at 1550 nm [0040]. However, since the claimed process for obtaining the preform from which an optical fiber is obvious (See rejection of Claim 8 above) and the combination of references suggests the relationship between concentrations of recited dopants, refractive index, and attenuation, it would have been obvious to modify the process of the combination of references to achieve an optical fiber from a preform using the obvious method of Claim 8 with claimed properties through routine optimization.
Regarding Claim 13, US’900 teaches forming an outer cladding region by depositing silica soot on the fluorine-doped cladding cane to form a porous overclad soot blank, the outer cladding region having a relative refractive index A4, consolidating the porous overclad soot blank to form a preform; and drawing the optical fiber from the preform (col. 5, lines 6-9; col. 9, lines 48-51; col. 10, lines 42-67). US’900 fails to teach Δ4- Δ3min > 0.05%. US’900 teaches a depressed index cladding portion (inner cladding) with a relative refractive index Δ 3 with a minimum relative refractive index in a range from -0.70% to -0.39% (Table 1; col. 1, lines 30-34) and embodiments in which both inner and outer cladding have Δ3- Δ2 = +- 0.05% (Claim 11; Figs. 5-6, 13-14; col. 6, lines 54-58), including embodiments where outer cladding exhibits a greater delta % than inner cladding (Figs. 13-14; col. 5, lines 49-54). US’392 suggests a refractive index difference between core and cladding of between 0.2%Δ and 0.5%Δ [0049], which is related to relative thicknesses and doping concentrations [0069-0070]. Additionally, US’392 teaches a depressed region inner cladding and an intermediate outer cladding relative index profile (Fig. 2A; [0056]). The combination of US’900 in view of US’392 having suggested the claimed method, recited desirable properties of an optical fiber can be achieved through routine optimization of the obvious process. Additionally, the combination of references provides evidence that the relationship Δ4- Δ3min > 0.05% is an optimizable variable to achieve a desirable relative refractive index profile within an optical fiber.
Additionally, US’900 teaches drawing an optical fiber from a preform comprising a fluorine-doped cladding cane (col. 5, lines 6-9; col. 9, lines 48-51; col. 10, lines 42-67) and an attenuation at 1550 nm of less than 0.175 dB/km (Claims 15-16). US’900 fails to teach an attenuation <0.16 dB/km at 1583 nm or an incremental attenuation above baseline at 1583 nm less than 0.0005 dB/km. However, since it is standard to report measurements at a wavelength of 1550 nm and not at 1570 nm, 1583 nm, and 1590 nm, it is not clear whether a drawn optical fiber in US’900 or as suggested by the combination of references would exhibit the claimed properties. Likewise, US’392 teaches an attenuation of less than 0.17 dB/km at 1550 nm (Abstract), including less than 0.16 dB/km and less than 0.15 dB/km at 1550 nm [0040]. However, since the claimed process for obtaining the preform from which an optical fiber is obvious (See rejection of Claim 9 above) and the combination of references suggests the relationship between concentrations of recited dopants, refractive index, and attenuation, it would have been obvious to modify the process of the combination of references to achieve an optical fiber from a preform using the obvious method of Claim 9 with claimed properties through routine optimization.
Regarding Claim 14, US’900 fails to teach expressly a negative limitation of exposing the porous overclad soot blank to the fluorine-doping precursor in the absence of SiCl4. US’392 suggests that chlorine is an optional dopant [0054], which would thus be obvious to omit. Therefore, it would have been obvious to omit SiCl4 as a source of optional chlorine.
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mishra (US 7,088,900) in view of Bookbinder et al. (US 2016/0304392) a applied to Claim 10 above, and further in view of Bookbinder et al. (US 2020/0049881).
Regarding Claim 11, US’900 teaches the step of forming the alkali-doped core cane comprises evaporating an alkali halide precursor and flowing it through a substrate tube (col. 9, lines 3-8); traversing a heating burner on the outside of the substrate tube with the alkali halide vapor flowing through the tube allowing alkali to dope the inside of the substrate tube and diffusing through the tube wall (col. 9, lines 8-19); collapsing the substrate tube to form a portion of the core cane (col. 9, lines 25-32). See rejection of Claims 1 and 8 concerning concentration limitations. US’900 teaches 0.1 wt. % (1000 ppm) of alkali metal oxide an endpoint (col. 4, lines 42-44). The combination of US’900 in view of US’392 fails to teach between 0.5% and 1.5 % wt. Bookbinder et al. (US’881) is analogous art in the field of manufacturing a preform of an optical fiber with core and cladding regions, and in addition teaches that the core can contain 0.5 wt % of potassium oxide (K2O), which is an alkali oxide [0056]. Moreover, US’881 provides evidence that the concentration of K2O is a result-effective variable, known in the art to affect the attenuation performance (id). It would have been obvious to a person of ordinary skill in the art at the time of invention to modify the process of the combination of US’900 in view of US’392 by providing alkali metal oxide within the recited amounts through routine optimization.
Claim(s) 16 and 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mishra (US 7,088,900) in view of Bookbinder et al. (US 2016/0304392), Bookbinder et al. (US 2016/0009588), and Bookbinder et al. (US 2020/0049881).
Regarding Claims 16 and 20, the combination of US’900 in view of US’392 teaches an optical fiber made by a method of manufacturing a preform of an optical fiber, the optical fiber having a glass core region (col. 8, lines 31-33) and a cladding region (Abstract), the method comprising forming a depressed-index region comprising silica glass doped with a first concentration of fluorine, the depressed-index region having a relative refractive index within the recited range and which is otherwise an optimizable parameter (see, also, rejection of Claim 6 above); and an outer cladding region surrounding and directly adjacent to the depressed-index cladding region, the outer cladding region comprising silica glass doped with a second concentration of fluorine less than the first concentration of fluorine (See, also, rejection of Claim 5 above). It would have been obvious to achieve through routine optimization the relationship Δ4- Δ3min > 0.05% is an optimizable variable to achieve a desirable relative refractive index profile within an optical fiber (see, also, rejection of Claim 6above) and the claimed attenuation values (see, also, rejection of Claim 10 above). US’900 teaches a depressed index cladding portion (inner cladding) with a relative refractive index Δ 3 with a relative refractive index in a range from -0.70% to -0.39% (Table 1; col. 1, lines 30-34) and therefore would have suggested a minimum Δ 3 (i.e. Δ 3min less than -0.3%).
The combination of US’900 in view of US’392 fails to teach time-to-peak hydrogen aging; however, given that the combination of US’900 and US’392 suggests the claimed process for forming an optical fiber with identical or obviously similar materials and properties, the hydrogen aging value is considered to be an obviously similar property of the resulting optical product absent evidence that hydrogen aging is a property that is independent of other properties or compositions taught in the combination of references for achieving that property. Additionally, Bookbinder et al. (US’588) is analogous art for an optical fiber and a process for making it and suggests that a mixture of carrier gas, including a source of chlorine gas and a reducing gas, reduces oxygen-rich defects reducing TTP during hydrogen aging testing and results in an optical fiber with TTP hydrogen aging value at 23 C of less than 100 hours [0014]. It would have been obvious to a person of ordinary skill in the art at the time of invention to modify the optical fiber of the combination of US’900 in view of US’392 with the recited hydrogen aging value, because US’588 suggests the modification by including a reducing gas during its fabrication.
US’900 teaches 0.1 wt. % (1000 ppm) of alkali metal oxide an endpoint (col. 4, lines 42-44). The combination of US’900 in view of US’392 and US’588 fails to teach between 0.5% and 1.5 % wt. Bookbinder et al. (US’881) is analogous art in the field of manufacturing a preform of an optical fiber with core and cladding regions, and in addition teaches that the core can contain 0.5 wt % of potassium oxide (K2O), which is an alkali oxide [0056]. Moreover, US’881 provides evidence that the concentration of K2O is a result-effective variable, known in the art to affect the attenuation performance (id). Thus, it would have been obvious to provide alkali metal oxide in a concentration within the recited range through routine optimization.
Regarding a concentration of SiCl4 in a depressed-index cladding region, US’900 teaches that there can be chlorine in the cladding (col. 5, lines 10-15), but fails to teach SiCl4. US’392 teaches that SiCl4 can be a source of chlorine dopants [0047] and teaches placing the soot preform – the core with silica soot deposited on it – in an atmosphere, containing 32% SiCl4 [0107] and recognizes the effect of chlorine doping on attenuation [0066]. Additionally, US’392 recognizes Cl from the SiCl4- dopant in the cladding [0077]. The combination of US’900 in view of US’392 fails to teach a specific concentration of SiCl4 in a cladding portion. US’588 teaches an optical fiber with a cladding layer with a chlorine content from a SiCl4 dopant of greater than 500 ppm wt. (Abstract; [0005,0014,0057]). US’881 also teaches that the cladding may include Cl dopant as an “up-dopant” and/ or an F “down-dopant” [0055,0042], the concentration of each of which is a result-effective variable known in the prior art to affect refractive index [0042]. Suggested concentrations of up-dopant, including Cl, range between about 0.01 wt% about 3 wt% (about 100 ppm to about 30000 ppm [0055]. Thus, it would have been obvious to a person of ordinary skill in the art at the time of invention to modify the optical fiber to include SiCl4 within the claimed range of greater than 200 ppm and also in the claimed ranges relative to the concentration of fluorine through routine optimization of up- and down-dopants to achieve a desired refractive index.
Regarding Claims 18-19, see discussion above about attenuation and incremental attenuation in Claim 10. US’900 teaches drawing an optical fiber from a preform comprising a fluorine-doped cladding cane (col. 5, lines 6-9; col. 9, lines 48-51; col. 10, lines 42-67) and an attenuation at 1550 nm of less than 0.175 dB/km (Claims 15-16). US’900 fails to teach an attenuation <0.16 dB/km at 1583 nm or an incremental attenuation above baseline at 1583 nm less than 0.0005 dB/km. However, since it is standard to report measurements at a wavelength of 1550 nm and not at 1570 nm, 1583 nm, and 1590 nm, it is not clear whether a drawn optical fiber in US’900 or as suggested by the combination of references would exhibit the claimed properties. Likewise, US’392 teaches an attenuation of less than 0.17 dB/km at 1550 nm (Abstract), including less than 0.16 dB/km and less than 0.15 dB/km at 1550 nm [0040]. However, since the claimed process for obtaining the preform from which an optical fiber is obvious (See, also, rejections of Claims 8 and 16 above) and the combination of references suggests the relationship between concentrations of recited dopants, refractive index, and attenuation, it would have been obvious to modify the process of the combination of references to achieve an optical fiber from a preform using the obvious method of Claim 8 with claimed properties through routine optimization.
Response to Arguments
Applicant’s amendment to the claims, filed 3 November 2025, with respect to the rejections of Claims 13-14 under 35 USC 112(b) and (d) have been fully considered and overcome the previous rejections under these paragraphs. The rejections of Claims 13-14 under 35 USC 112(b) and (d) have been withdrawn.
Applicant's arguments filed 03 November 2025, with respect to the rejection of Claim 20 under 35 USC 112(b) and the rejections of Claims 1-8, 10-11,13,17, and 18-20 under 35 USC 103 have been fully considered but they are not persuasive.
Although the Remarks aver that Claim 20 has been cancelled (Remarks, p. 1), it has not been cancelled.
In response to Applicant’s argument that US’392 fails to teach chlorine in the cladding region (Remarks, p. 9, third paragraph to p. 10), US’900 teaches that there can be chlorine in the cladding (col. 5, lines 10-15), but fails to teach SiCl4. US’392 teaches that SiCl4 can be a source of chlorine dopants [0047] and teaches placing the soot preform – the core with silica soot deposited on it – in an atmosphere, containing 32% SiCl4 [0107] and recognizes the effect of chlorine doping on attenuation [0066]. The core and cladding are both formed of silica [0053-0054] and would be expected to be similarly affected by similar dopants. Additionally, US’392 recognizes Cl from the SiCl4- dopant in the cladding [0054,0077]. The combination of US’900 in view of US’392 fails to teach a specific concentration of SiCl4 in a cladding portion. US’588 teaches an optical fiber with a cladding layer with a chlorine content from a SiCl4 dopant of greater than 500 ppm wt. (Abstract; [0005,0014,0057]). US’881 also teaches that the cladding may include Cl dopant as an “up-dopant” and/ or an F “down-dopant” [0055,0042], the concentration of each of which is a result-effective variable known in the prior art to affect refractive index [0042]. Suggested concentrations of up-dopant, including Cl, range between about 0.01 wt% about 3 wt% (about 100 ppm to about 30000 ppm [0055]. In addition, Ishikawa et al. (US 6,116,055) provides evidence that it has been known at least as far back as year 2000 to control the refractive index and the refractive index difference in a depressed-cladding structure by controlling SiCl4 concentration, including in the range of 3 to 20 vol. % (col. 5, lines 40-50) and including an amount in the cladding (col. 7, lines 3-6 and 16-25). US’055 also presents a clear picture of how soot preforms of both core and cladding can be viewed as multiple depositions and doping of multiple layers of soot are produced with soot deposition to form a soot preform for a core and a soot preform, where doping with dopants, including SiCl4 are used to adjust refractive index in each layer (cols. 6-7). Thus, it would have been obvious to a person of ordinary skill in the art at the time of invention to modify the optical fiber to include SiCl4 within the claimed range of greater than 200 ppm and also in the claimed ranges relative to the concentration of fluorine through routine optimization of up- and down-dopants to achieve a desired refractive index based on the combinations cited in the rejections, given the understanding of the effects of various dopants, including SiCl4 and fluorine, on the properties of an optic fiber.
In response to Applicant’s argument that Mishra teaches away from doping with Cl when it says that it is preferable that a tube be essentially chlorine free” (Remarks, p. 10, second paragraph; p. 11, last paragraph; p. 13), a preference is not a teaching away, Moreover, despite Applicant’s emphasis on a silica glass tube in column 8, Mishra teaches that chlorine can be in both core and cladding (col. 5, lines 10-27).
Conclusion
No claim is allowed.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER M WEDDLE whose telephone number is (571)270-5346. The examiner can normally be reached 9:30-6:30.
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ALEXANDER M WEDDLE
Examiner
Art Unit 1712
/ALEXANDER M WEDDLE/Primary Examiner, Art Unit 1712